<?php
/**
 * Bonfire
 *
 * An open source project to allow developers to jumpstart their development of
 * CodeIgniter applications.
 *
 * @package Bonfire
 * @filesource
 */

/**
 * Portable PHP password hashing framework.
 *
 * Originally written by Solar Designer <solar at openwall.com> in 2004-2006 and
 * placed in the public domain. Revised in subsequent years, still public domain.
 *
 * There's absolutely no warranty.
 *
 * Please be sure to update the Version line if you edit this file in any way.
 * It is suggested that you leave the main version number intact, but indicate
 * your project name (after the slash) and add your own revision information.
 *
 * Please do not change the "private" password hashing method implemented in
 * here, thereby making your hashes incompatible. However, if you must, please
 * change the hash type identifier (the "$P$") to something different.
 *
 * Obviously, since this code is in the public domain, the above are not
 * requirements (there can be none), but merely suggestions.
 *
 * Version 0.3 / bonfire.
 *  - Supress PHP errors generated by is_readable('/dev_urandom'),
 *    in particular from open_basedir restriction.
 *  - Remove support for PHP 4
 *  - Update code to use visibility modifiers and PHP 5 constructor
 *
 * @package Bonfire\Modules\Users\Libraries\PasswordHash
 * @author  Solar Designer <solar at openwall.com>
 * @author  Bonfire Dev Team
 * @license Public Domain
 * @version 0.3 / bonfire
 * @link    http://www.openwall.com/phpass/
 */
class PasswordHash
{
    // -------------------------------------------------------------------------
    // Protected Properties - intended for internal use only
    // -------------------------------------------------------------------------

    /**
     * @deprecated since 0.8.2 - will be protected in a future version
     * @var integer
     */
    public $iteration_count_log2;

    /**
     * @deprecated since 0.8.2 - will be protected in a future version
     * @var string
     */
    public $itoa64;

    /**
     * @deprecated since 0.8.2 - will be protected in a future version
     * @var boolean
     */
    public $portable_hashes;

    /**
     * @deprecated since 0.8.2 - will be protected in a future version
     * @var string
     */
    public $random_state;

    /**
     * Constructor
     *
     * @param integer $iteration_count_log2 The number of iterations to use when
     * hashing passwords.
     * @param boolean $portable_hashes      Whether the "portable" hashing algorithm
     * should be used.
     *
     * @return void
     */
    public function __construct($iteration_count_log2, $portable_hashes)
    {
        $this->itoa64 = './0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';

        if ($iteration_count_log2 < 4 || $iteration_count_log2 > 31) {
            $iteration_count_log2 = 8;
        }

        $this->iteration_count_log2 = $iteration_count_log2;
        $this->portable_hashes = $portable_hashes;
        $this->random_state = microtime();
        if (function_exists('getmypid')) {
            $this->random_state .= getmypid();
        }
    }

    /**
     * Check whether a plain-text password matches a hashed password.
     *
     * @param string $password    The plain-text password.
     * @param string $stored_hash The hashed password.
     *
     * @return boolean True if the passwords match, else false.
     */
    public function CheckPassword($password, $stored_hash)
    {
        $hash = $this->crypt_private($password, $stored_hash);
        if ($hash[0] == '*') {
            $hash = crypt($password, $stored_hash);
        }

        return $hash == $stored_hash;
    }

    /**
     * Hash a password so it can be stored securely.
     *
     * @param string $password The plain-text password to be hashed.
     *
     * @return string The hashed password.
     */
    public function HashPassword($password)
    {
        $random = '';
        if (CRYPT_BLOWFISH == 1 && ! $this->portable_hashes) {
            $random = $this->get_random_bytes(16);
            $hash = crypt($password, $this->gensalt_blowfish($random));
            if (strlen($hash) == 60) {
                return $hash;
            }
        }

        if (CRYPT_EXT_DES == 1 && ! $this->portable_hashes) {
            if (strlen($random) < 3) {
                $random = $this->get_random_bytes(3);
            }

            $hash = crypt($password, $this->gensalt_extended($random));
            if (strlen($hash) == 20) {
                return $hash;
            }
        }

        if (strlen($random) < 6) {
            $random = $this->get_random_bytes(6);
        }

        $hash = $this->crypt_private($password, $this->gensalt_private($random));
        if (strlen($hash) == 34) {
            return $hash;
        }

        // Returning '*' on error is safe here, but would _not_ be safe in a crypt(3)-like
        // function used _both_ for generating new hashes and for validating passwords
        // against existing hashes.
        return '*';
    }

    // -------------------------------------------------------------------------
    // Protected Methods - intended for internal use only
    // -------------------------------------------------------------------------

    /**
     * @deprecated since 0.8.2 - will be protected in a future version
     * @param  integer $count
     * @return string
     */
    public function get_random_bytes($count)
    {
        $output = '';
        if (@is_readable('/dev/urandom') &&
            ($fh = @fopen('/dev/urandom', 'rb'))) {
            $output = fread($fh, $count);
            fclose($fh);
        }

        if (strlen($output) < $count) {
            $output = '';
            for ($i = 0; $i < $count; $i += 16) {
                $this->random_state =
                    md5(microtime() . $this->random_state);
                $output .=
                    pack('H*', md5($this->random_state));
            }
            $output = substr($output, 0, $count);
        }

        return $output;
    }

    /**
     * @deprecated since 0.8.2 - will be protected in a future version
     * @param  string $input
     * @param  integer $count
     * @return string
     */
    public function encode64($input, $count)
    {
        $output = '';
        $i = 0;
        do {
            $value = ord($input[$i++]);
            $output .= $this->itoa64[$value & 0x3f];
            if ($i < $count) {
                $value |= ord($input[$i]) << 8;
            }

            $output .= $this->itoa64[($value >> 6) & 0x3f];
            if ($i++ >= $count) {
                break;
            }

            if ($i < $count) {
                $value |= ord($input[$i]) << 16;
            }

            $output .= $this->itoa64[($value >> 12) & 0x3f];
            if ($i++ >= $count) {
                break;
            }

            $output .= $this->itoa64[($value >> 18) & 0x3f];
        } while ($i < $count);

        return $output;
    }

    /**
     * @deprecated since 0.8.2 - will be protected in a future version
     * @param  string $input
     * @return string
     */
    public function gensalt_private($input)
    {
        $output = '$P$';
        $output .= $this->itoa64[min($this->iteration_count_log2 + 5, 30)];
        $output .= $this->encode64($input, 6);

        return $output;
    }

    /**
     * @deprecated since 0.8.2 - will be protected in a future version
     * @param  string $password
     * @param  string $setting
     * @return string
     */
    public function crypt_private($password, $setting)
    {
        $output = '*0';
        if (substr($setting, 0, 2) == $output) {
            $output = '*1';
        }

        $id = substr($setting, 0, 3);
        // We use "$P$", phpBB3 uses "$H$" for the same thing
        if ($id != '$P$' && $id != '$H$') {
            return $output;
        }

        $count_log2 = strpos($this->itoa64, $setting[3]);
        if ($count_log2 < 7 || $count_log2 > 30) {
            return $output;
        }

        $count = 1 << $count_log2;

        $salt = substr($setting, 4, 8);
        if (strlen($salt) != 8) {
            return $output;
        }

        // We're kind of forced to use MD5 here since it's the only cryptographic
        // primitive available in all versions of PHP currently in use. To implement
        // our own low-level crypto in PHP would result in much worse performance
        // and consequently in lower iteration counts and hashes that are quicker
        // to crack (by non-PHP code).
        $hash = md5($salt . $password, true);
        do {
            $hash = md5($hash . $password, true);
        } while (--$count);

        $output = substr($setting, 0, 12);
        $output .= $this->encode64($hash, 16);

        return $output;
    }

    /**
     * @deprecated since 0.8.2 - will be protected in a future version
     * @param  string $input
     * @return string
     */
    public function gensalt_extended($input)
    {
        $count_log2 = min($this->iteration_count_log2 + 8, 24);
        // This should be odd to not reveal weak DES keys, and the maximum valid
        // value is (2**24 - 1) which is odd anyway.
        $count = (1 << $count_log2) - 1;

        $output = '_';
        $output .= $this->itoa64[$count & 0x3f];
        $output .= $this->itoa64[($count >> 6) & 0x3f];
        $output .= $this->itoa64[($count >> 12) & 0x3f];
        $output .= $this->itoa64[($count >> 18) & 0x3f];

        $output .= $this->encode64($input, 3);

        return $output;
    }

    /**
     * @deprecated since 0.8.2 - will be protected in a future version
     * @param  string $input
     * @return string
     */
    public function gensalt_blowfish($input)
    {
        // This one needs to use a different order of characters and a different
        // encoding scheme from the one in encode64() above. We care because the
        // last character in our encoded string will only represent 2 bits. While
        // two known implementations of bcrypt will happily accept and correct a
        // salt string which has the 4 unused bits set to non-zero, we do not want
        // to take chances and we also do not want to waste an additional byte of
        // entropy.
        $itoa64 = './ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';

        $output = '$2a$';
        $output .= chr(ord('0') + $this->iteration_count_log2 / 10);
        $output .= chr(ord('0') + $this->iteration_count_log2 % 10);
        $output .= '$';

        $i = 0;
        do {
            $c1 = ord($input[$i++]);
            $output .= $itoa64[$c1 >> 2];
            $c1 = ($c1 & 0x03) << 4;
            if ($i >= 16) {
                $output .= $itoa64[$c1];
                break;
            }

            $c2 = ord($input[$i++]);
            $c1 |= $c2 >> 4;
            $output .= $itoa64[$c1];
            $c1 = ($c2 & 0x0f) << 2;

            $c2 = ord($input[$i++]);
            $c1 |= $c2 >> 6;
            $output .= $itoa64[$c1];
            $output .= $itoa64[$c2 & 0x3f];
        } while (1);

        return $output;
    }
}
